Gas Chromatography-Mass Spectrometry-Based Targeted Metabolomics of Hard Coral Samples.

Gas chromatography-mass spectrometry (GC-MS)-based approaches have proven to be powerful for elucidating the metabolic basis of the cnidarian-dinoflagellate symbiosis and how coral responds to stress (i.e., during temperature-induced bleaching). Steady-state metabolite profiling of the coral holobiont, which comprises the cnidarian host and its associated microbes (Symbiodiniaceae and other protists, bacteria, archaea, fungi, and viruses), has been successfully applied under ambient and stress conditions to characterize the holistic metabolic status of the coral. However, to answer questions surrounding the symbiotic interactions, it is necessary to analyze the metabolite profiles of the coral host and its algal symbionts independently, which can only be achieved by physical separation and isolation of the tissues, followed by independent extraction and analysis. While the application of metabolomics is relatively new to the coral field, the sustained efforts of research groups have resulted in the development of robust methods for analyzing metabolites in corals, including the separation of the coral host tissue and algal symbionts. This paper presents a step-by-step guide for holobiont separation and the extraction of metabolites for GC-MS analysis, including key optimization steps for consideration. We demonstrate how, once analyzed independently, the combined metabolite profile of the two fractions (coral and Symbiodiniaceae) is similar to the profile of the whole (holobiont), but by separating the tissues, we can also obtain key information about the metabolism of and interactions between the two partners that cannot be obtained from the whole alone.

Identifying Factors of Operative Efficiency in Head and Neck Free Flap Reconstruction.

Importance: Head and neck oncological resection and reconstruction is a complex process that requires multidisciplinary collaboration and prolonged operative time. Numerous factors are associated with operative time, including a surgeon's experience, team familiarity, and the use of new technologies. It is paramount to evaluate the contribution of these factors and modalities on operative time to facilitate broad adoption of the most effective modalities and reduce complications associated with prolonged operative time. Objective: To examine the association of head and neck cancer resection and reconstruction interventions with operative time. Design, Setting, and Participants: This large cohort study included all patients who underwent head and neck oncologic resection and free flap-based reconstruction in Calgary (Alberta, Canada) between January 1, 2007, and March 31, 2020. Data were analyzed between November 2021 and May2022. Interventions: The interventions that were implemented in the program were classified into team-based strategies and the introduction of new technology. Team-based strategies included introducing a standardized operative team, treatment centralization in a single institution, and introducing a microsurgery fellowship program. New technologies included use of venous coupler anastomosis and virtual surgical planning. Main Outcomes and Measures: The primary outcome was mean operative time difference before and after the implementation of each modality. Secondary outcomes included returns to the operating room within 30 days, reasons for reoperation, returns to the emergency department or readmissions to hospital within 30 days, and 2-year and 5-year disease-specific survival. Multivariate regression analyses were performed to examine the association of each modality with operative time. Results: A total of 578 patients (179 women [30.9%]; mean [SD] age, 60.8 [12.9] years) undergoing 590 procedures met inclusion criteria. During the study period, operative time progressively decreased and reached a 32% reduction during the final years of the study. A significant reduction was observed in mean operative time following the introduction of each intervention. However, a multivariate analysis revealed that team-based strategies, including the use of a standardized nursing team, treatment centralization, and a fellowship program, were significantly associated with a reduction in operative time. Conclusions: The results of this cohort study suggest that among patients with head and neck cancer, use of team-based strategies was associated with significant decreases in operative time without an increase in complications.

Patient-Reported Outcomes after Fibula Free Flap Harvest: A Pilot Study.

SUMMARY: Patient-reported outcomes regarding donor-site morbidity and quality of life for the fibula free flap in head and neck reconstruction patients have not been studied. The authors reviewed and identified patients who had undergone head and neck reconstruction using a fibula free flap (2011 to 2016). Patients were assessed via physical examination and two patient-reported outcomes questionnaires: the Foot and Ankle Outcome Score (score range, 0 to 100) and the Pain Disability Questionnaire (score range, 0 to 100). Quantitative data were analyzed with appropriate statistical tests. Semistructured interviews exploring donor-site challenges were performed and analyzed using thematic analysis. Seventeen patients agreed to participate. Their mean age was 62 years (range, 41 to 81 years). Mean follow-up was 38 months (range, 12 to 65 years). Mean perceived level of function compared to baseline was 67 percent. Mean scores for the Foot and Ankle Outcome Score subscales were 84.6 (pain), 80.5 (symptoms), 86.7 (activities of daily living), 67.7 (sport), and 65.6 (quality of life). The mean Pain Disability Questionnaire score was 26.3 (mild/moderate perceived disability). Higher perceived level of function was associated with higher Foot and Ankle Outcome Score values (pain, symptoms, and activities of daily living, p < 0.05). Donor limbs had decreased range of motion and manual muscle testing scores compared with their contralateral limbs (p < 0.05). Lack of ankle support and balance, resulting in limitations and aversions to daily and sporting activities, were the most common themes regarding donor-site challenges. In conclusion, patients who have undergone fibula free flap harvest struggle with ankle support and balance and face functional difficulties that have an impact on their quality of life. Multidisciplinary approaches for targeted rehabilitation after fibula free flap harvest should be explored to determine the impact on patients' quality of life.

Evaluating CNVII Recovery after Reconstruction with Vascularized Nerve Grafts: A Retrospective Case Series.

Few studies have evaluated vascularized nerve grafts (VNGs) for facial nerve (CNVII) reconstruction. We sought to evaluate long-term outcomes for CNVII recovery following reconstruction with VNGs. A retrospective review of all patients at a tertiary centre who underwent radical parotidectomy and immediate CNVII reconstruction with VNGs was performed (January 2009-December 2019). Preoperative demographics, perioperative factors (flap type, source of VNGs), and postoperative factors [complications, adjuvant therapy, revisionary procedures, length of follow-up, and CNVII function via the House-Brackmann scale (HB)] were collected. Data were summarized qualitatively. Twelve patients (Mage = 53 ± 18 years) with a mean follow-up of 33 (± 23) months were included. Six patients underwent reconstruction with a radial forearm flap and dorsal sensory branches of the radial nerve. Six patients underwent reconstruction with an anterolateral thigh flap and only deep motor branches of the femoral nerve to the vastus lateralis (n = 4) or combined with the lateral femoral cutaneous nerve (n = 2). Two patients regained nearly normal function (HB = 2). Eight patients regained at least resting symmetry (HB = 3 for n = 7; HB = 4 for n = 1). One patient regained a flicker of movement (HB = 5). One patient did not regain function (HB = 6). Six patients had static revision procedures to improve symmetry. Five patients had disease recurrence; 3 died from their disease. VNGs offer a practical and viable addition to the CNVII reconstruction strategy, and result in good functional recovery with acceptable donor site deficits. The associated adipofascial component of these flaps can also augment the soft tissue defect left after tumor ablation.

Novel Plate Design to Improve Mandibular and Maxillary Reconstruction with the Osteocutaneous Fibula Flap.

Virtual surgical planning (VSP) has improved the accuracy and efficiency of craniofacial reconstruction using the osteocutaneous free fibula flap. Despite this, challenges remain in translating the VSP to a real-world construct due to small changes that can occur after osteotomies of the mandible or maxilla. Poor execution of the VSP can lead to malocclusion, undesirable aesthetics, or poor bony contact at the sites of osteosynthesis. We describe a novel technique using Selective LASER Melted plates to achieve maximum control and accuracy of complex, virtually planned reconstructions of the mandible and maxilla.

One Versus 2 Venous Anastomoses in Free Flap Surgery: A Systematic Review and Meta-Analysis.

BACKGROUND: The necessity of a second venous anastomosis in free flap surgery is controversial. The purpose of this systematic review is to determine whether venous flap failure and reoperation rates are lower when 2 venous anastomoses are performed. The secondary objective is to determine whether venous flap failure and reoperation rates are lower when the 2 veins are from 2 different drainage systems. METHODS: A comprehensive search of the literature identified relevant studies. Investigators independently extracted data on rates of flap failure and reoperation secondary to venous congestion. A meta-analysis was performed; odds ratios (ORs) were pooled using a random-effects model and 95% confidence intervals (CIs). RESULTS: Of 18 190 studies identified, 15 were included for analysis. The mean sample size was 287 patients (minimum = 102, maximum = 564). No statistically significant difference in venous flap failure was found when comparing 1 versus 2 venous anastomoses (OR: 1.35; 95% CI: 0.46-3.93). A significant decrease in reoperation rate due to venous congestion was shown (OR: 3.03; 95% CI: 1.64-5.58). The results favor using 2 veins from 2 different systems over veins from the same system (OR: 0.16; 95% CI: 0.02-1.27). CONCLUSIONS: There is low-quality evidence suggesting that the use of 2 venous anastomoses will lower the rate of reoperation due to venous congestion. There are insufficient data published to meaningfully compare outcomes of flaps with 2 venous anastomoses from different systems to flaps with anastomoses from the same system.

HISTORIQUE: La nécessité d'une deuxième anastomose veineuse lors d'une opération par lambeau libre est matière à controverse. La présente analyse systématique visait à déterminer si l'échec du lambeau veineux et le taux de réopération étaient plus faibles après deux anastomoses veineuses. L'objectif secondaire consistait à déterminer si l'échec du lambeau veineux et le taux de réopération étaient plus faibles lorsque les deux veines provenaient de deux systèmes de drainage différents. MÉTHODOLOGIE: Les chercheurs ont repéré les études pertinentes au moyen d'une recherche approfondie des publications. De manière indépendante, ils ont extrait les données sur le taux d'échec des lambeaux et des réopérations après une congestion veineuse. Ils ont procédé à une méta-analyse et ont regroupé les rapports de cote (RC) au moyen d'un modèle à effet aléatoire et d'intervalles de confiance (IC) à 95 %. RÉSULTATS: Sur les 18 190 études extraites, les chercheurs en ont inclus 15 dans l'analyse. Leur échantillon moyen était de 287 patients (minimum 102, maximum 564). Ils n'ont pas constaté de différence statistiquement significative des échecs des lambeaux lorsqu'ils comparaient une ou deux anastomoses veineuses (RC 1,35; IC à 95 % 0,46 à 3,93). Ils ont constaté une diminution significative du taux de réopérations attribuables à une congestion veineuse (RC 3,03; IC à 95 % 1,64 à 5,58). Les résultats favorisent le recours à deux veines de deux systèmes veineux différents plutôt que d'un même système (RC 0,16; IC à 95 % 0,02 à 1,27). CONCLUSIONS: Selon des preuves de faible qualité, le recours à deux anastomoses veineuses réduit le taux de réopérations attribuables à une congestion veineuse. Les données publiées sont insuffisantes pour comparer de manière significative les résultats des lambeaux de deux anastomoses provenant de systèmes différents à ceux des lambeaux provenant d'un même système.

Vertical Scar Breast Reduction: Does Gathering the Incision Matter?

BACKGROUND: The vertical scar bilateral breast reduction is a highly effective technique to reduce breast volume and create long-lasting aesthetic improvements. A cited disadvantage is the inability to adequately shorten the vertical scar, leading to chest wall scars or inframammary puckers. Gathering or cinching sutures have been described as a strategy to confront this issue. This article aims to determine if suture gathering is an effective methods to (1) reduce the incision length, (2) shorten the areola-to-inframammary fold (IMF) distance, and (3) reduce the pucker revision rate. METHODS: All patients undergoing vertical breast reduction performed by the senior author (E.H.F.) from 2001 to 2007 were included. The patient population was divided into "gather" and "no gather" groups depending on how the vertical incision was closed. RESULTS: There were 203 patients in the "no gather" group and 193 in the "gather" group. Age, body mass index, and resection weight were statistically but not clinically different. The percent reduction in vertical incision length was significantly greater in the "gather" group (34.2 ± 9.9% vs. 12.2 ± 5.9%). Both groups showed a gradual lengthening of areola-to-IMF distance postoperatively. Suture gathering had no impact on the pucker revision rate but increased healing complications. CONCLUSION: Gathering sutures significantly reduce the incision length in the operating room but do not change the areola-to-IMF distance or pucker revision rate. Gathering negatively influences skin vascularity and wound healing. It is acceptable and necessary to have a longer areola-to-IMF distance in a vertical reduction to accommodate increased projection.

Distribution and genetic characterization of Mycobacterium chelonae in laboratory zebrafish Danio rerio.

During routine screening of zebrafish at a research facility, histological changes consistent with mycobacteriosis were observed, prompting an investigation to determine the background prevalence and distribution of Mycobacterium species throughout the facility. Infection status was evaluated in 240 zebrafish representing 9 genetic lines, using histology, culture and PCR. Environmental sources were also tested for the presence of mycobacteria. Prevalence in zebrafish by culture and PCR was 10% (24/240), 21 of which were TU line fish. All isolates from fish were identified as M. chelonae by hsp65 DNA sequencing; subsequent DNA fingerprinting delineated 3 strains, designated H1E1 (1/24), H1E2 (22/24), and H1E3 (1/24). From external sources, tank or tubing surface biofilms were positive by culture (13/32) with multiple species and strains isolated including M. neoaurum, M. phocaicum, and identical strains of M. chelonae that were found in zebrafish: H1E1 (2/13) and H1E2 (8/13). Comparing diagnostic methods, acid-fast stained histological sections showed substantial agreement with plate culture and PCR for detection of mycobacteria in fish. Observation of granulomas in hematoxylin and eosin-stained sections was a less reliable predictor of mycobacteriosis, as uninfected females with egg-associated inflammation and hyperplasia were misdiagnosed. These data revealed background levels of mycobacteriosis in a healthy and well-managed facility. Infected populations were removed, although the apparent ability for M. chelonae to remain viable in environmental reservoirs may make it difficult to eradicate completely. This highlights the importance of an animal-health monitoring program and good husbandry practices to prevent disease in zebrafish research laboratories.

Indirect injury stimulates scar formation-adaptation or pathology?

In several animal models of osteoarthritis induced by cruciate ligament transection, a dense, scar-like tissue mass forms rapidly on the medial side of the knee joint. This mass mimics clinical fibrosis that sometimes occurs after joint surgery. It is unknown exactly why this medial tissue mass forms and what cells are involved in its formation. This study characterizes this medial mass by histology, biochemistry, and the expression of types I and III collagen mRNA. The medial mass is compared with the medial collateral ligament (MCL) and the MCL epiligament in anterior cruciate-transected and unoperated joints, and to normal skin and skin scar. The morphology of the medial mass resembled the epiligament and skin scar more than the MCL. The concentration of DNA and RNA and the RNA-DNA ratio were elevated dramatically in the medial mass compared with all other tissues including skin scar. However, the mRNA copy number and ratio of collagen types I and III mRNAs did not differ significantly among the medial mass, MCL, epiligament, and skin in either the control or the operated joints. The response of the medial mass, MCL, and MCL epiligament to cruciate transaction involves both hyperplasia and hypertrophy, but without a dramatic shift in cell phenotype. The medial mass may be a useful mimic or model of intraarticular adhesions, hypertrophic scars, ligament sprains, and arthrofibrosis.

Pseudocapillaria tomentosa, a nematode pathogen, and associated neoplasms of zebrafish (Danio rerio) kept in research colonies.

Infections with capillarid nematodes were observed in zebrafish (Danio rerio) kept at several research facilities and in a large carcinogen exposure study previously conducted at Oregon State University. We report a morphologic description that identifies the worm as Pseudocapillaria tomentosa, a common nematode of cyprinid and other fishes. Pathologic lesions associated with the infection ranged from inflammatory changes to aggressive neoplasms of the intestine (i.e., intestinal carcinomas and mixed malignant neoplasms). Capillarid nematodes may have intermediate or paratenic hosts. Using a laboratory transmission study, we confirmed that the parasite has a direct life cycle.